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Magnaflow Street Cat-Back Exhaust (99-04 GT, Mach 1)

32 Reviews
Our Price


  • Item #48012
  • MPN# 15671

  • Market Price $727.99
  • You Save 9% ($66.30)
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Product Videos Customer Photos
  • Classic Muscle Car Sound
  • Street Series Muffler - Straight-Through Design
  • Durable, Stainless Steel Construction
  • 2.5" Mandrel-Bent Tubing
  • 3.5" Polished Stainless Steel Tips
  • Fits 1999-2004 GT, Bullitt and Mach 1 Mustangs
Free Flowing Exhaust. Magnaflow delivers the ultimate exhaust for the 99-04 GT, Bullitt, and Mach 1 Mustangs with this Street Cat-Back Exhaust System. By reducing back pressure for a free flowing exhaust, more power and torque is produced where it belongs - at the rear wheels.

Classic Muscle Car Sound. The Magnaflow Cat-Back Exhaust System includes a set of two Street Series Mufflers that feature a free-flowing, straight-through perforated stainless steel core, with stainless mesh wrap and acoustical fiber fill to deliver that smooth, deep muscle car tone.

Quality Construction. Each piece of this Street Exhaust is made from 2.5" mandrel bent stainless steel tubing for long life and a perfect fit. The system is finished off with brightly polished 3.5" stainless steel tips that exit from the stock location for impressive good looks.

Application. Made to be a direct bolt on, this Magnaflow Street Cat-Back Exhaust will bolt straight up to the factory Mid Pipe without any extra modifications required on 1999-2004 GT, 2001 Bullitt or 2003-2004 Mach 1 Mustangs.

Note: Coupon codes cannot be applied to this product.

Lifetime Warranty is included with all Magnaflow catback systems.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (2) Flow Tubes
  • (2) Tail Pipes
  • (2) Mufflers
  • (2) Turn-Down Tips
  • (2) Set Screws w/ Allen Wrench
  • (2) Tip Hangers
  • (6) 1.25" x 2.5" Band Clamps
  • (2) Header Mounting Flanges
Installation Info
Tech Specs
Cat-Back Exhaust Specifications
Piping Material: Stainless Steel Tip Material : Polished Stainless Steel
Piping Size: 2.5" Tip Size: 3.5"
Muffler Type: Straight-through Fitment: 1999-2004 GT / Mach 1 / Bullitt
Will it fit my Mustang?
  • Bullitt - 01
  • Mach 1 - 03, 04
  • GT - 99, 00, 01, 02, 03, 04

Most Helpful Reviews

Fits and sounds great

Put this on my 99 GT. Took a little effort to get it all lined up but it is doable. With stock h-pipe the sound was a little deeper and louder than stock but not much. I then added an off-road x-pipe. ...

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Helpful (10)

New Exhaust

Just got it installed yesterday great sound, better acceleration. Way worth the money.

Helpful (6)

Overall Rating 4.8 out of 5 stars
Read All 32 Reviews

Review & Install Video

Hey I’m Justin with, and this is my quick look into the Magnaflow catback exhaust system fitting the 99-04 Mustang GT and Mach 1. Right off the bat, I can tell you this isn’t going to be the loudest kit in the world, thanks in part to the traditional chambered muffler design. What you can expect from this kit is for it to be slightly more aggressive than stock, when idle and while cruising, but really comes to life when you get on the throttle. Just because this system is a little on the quiet side doesn’t make it a bad exhaust, as a matter of fact it’s far from it. We’re looking at a full stainless steel constructions throughout, including 2.5” mandrel bent tubing, quality welds, and a quality finish, both on those chambered mufflers, and on those 3.5” flared polished tips. As the factory exhaust is all one piece you will need to cut it off with a saw or something similar, once you get that out of the way, getting the magnaflow installed is a very straightforward task, that should take you about 2 hours using standard hand tools. Now let’s hear how Magnaflow’s catback exhaust system sounds compared to your factory exhaust.

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4 Questions / 5 Answers

Ask a Question

Will this work with the sn95? Would this exhaust system fit the sn95? Can I just only modify the hangers so this setup can fit?


Answer This Question I need this answered (0) (0)

Magnaflow catback exhaust installation? The actual color of my 2004 GT is Merlot Clearcoat, but that option was not listed. My question is: do you need any type of heat shield between the mufflers and the floor pans to keep the inside floors from becoming too hot? The original factory mufflers had heat shields attached to the top of them.


  • I have never had any problem with heat with any after market exhaust, never needed a heat shield


    Good Answer (0) (0)

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Hi, roughly what kind of hp/torque can I get from bbk headers, magnaflow street catbacks and flowmaster catted h-pipes ? Standard is 260/302. Thanks, Frank


  • Power gains will be different for each setup, for example; if you have BBK Ceramic Tuned Length Shorty Headers (96-04 GT) item #56101 ( with Magnaflow Street Catbacks and Flowmaster Catted H-Pipes you can gain around 15HP. If you have BBK Ceramic Long Tube Headers - Manual (96-04 GT) item #56010 ( with a tune you could see 25-30HP.


    Good Answer (0) (0)

Question Resolved

Will this system fit my 99 SVT Cobra Mustang?


  • The Magnaflow Street Cat-Back Exhaust will only work with the 1999 to 2004 Mustang GT and Mach 1. For your 1999 Mustang SVT Cobra you will want to purchase Magnaflow Cat-Back Exhaust Item #48011 (


    Good Answer (0) (0)

Question Resolved

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Customer Reviews (32) Write a Review

Overall Rating 4.8

out of 5 stars

Installation Time:Full Day

Installation Cost:$100-$250

  • Loudness / Volume 4.222222 4.2
  • Exhaust Note 4.555555 4.6
  • Fit & Finish 4.5 4.5
  • Bang For Your Buck 4.166667 4.2

  • 5/5

    November 29, 2009

    Fits and sounds great

    Put this on my 99 GT. Took a little effort to get it all lined up but it is doable. With stock h-pipe the sound was a little deeper and louder than stock but not much. I then added an off-road x-pipe. This increased the volume. The sound is deep. At idle, there is little difference from stock. But when on the gas, it sounds great. Definitely does not sound like Flowmasters. There is no drone or resonance while driving.


    Year: 1999 Submodel: GT

    Helpful (10) (0)

  • 5/5

    June 29, 2010

    Very Nice Exhaust

    This kit is the best. The fit is perfect, not too loud when cruising but if you open her up she howls. When installing it's okay to lift by the frame but before you tighten everything up make sure to lift car but the differential so that you know the clearances are good. Very good exhaust for the money!!!


    Helpful (6) (0)

  • 5/5

    April 04, 2009

    New Exhaust

    Just got it installed yesterday great sound, better acceleration. Way worth the money.


    Helpful (6) (0)

  • 5/5

    November 18, 2009


    Awesome sounding Catback Exhaust setup.. I got this for my V6.. with O/R Pypes X pipe and BBK Shorty Headers. its an Awesome setup just need to Tune it now.. Overall Awesome Purchase.

    Joel Zervoulakos

    Helpful (5) (0)

  • 5/5

    September 02, 2009


    Put this on my '99 GT along with an AEM cold air and the AM strut tower brace and my car has never sounded or run better. I'll be back for more parts AM...


    Year: 1999 Submodel: GT

    Helpful (3) (0)

  • 4/5

    January 06, 2009


    I just put these on my 2004 GT and man do they sound great! For my completely stock GT, it made it a little louder, but more muffled sounding. A new air intake or headers would help out the sound too. Install was kind of easy, but taking out the rubber grommets took forever. Overall, it took about 2 hours, but looks fantastic!

    matt w

    Year: 2004 Submodel: GT

    Helpful (3) (0)

  • 5/5

    Installation Time: Shop Install

    January 03, 2012

    Great exhaust

    Great exhaust with an upgraded sound for your GT. I had a shop install it at the same time as my new clutch and it ran me about 550 together.


    Year: 1999 Submodel: GT Atlanta, GA

    Helpful (2) (0)

  • 5/5

    April 11, 2008


    My 04 GT was pretty quiet stock. After i installed the magnapacks along with the magnaflow o/r tru-x x-pipe the car sounded like a beast. The exhaust makes the car sound like an old muscle car at idle, but at WOT it sounds really crisp. ITS ALMOST TOO LOUD!! 100% worth the money. I have no regrets. Id buy this product again and i HIGHLY recommend it.


    Year: 2004 Submodel: GT

    Helpful (2) (0)

  • 5/5

    October 04, 2007

    Great Product

    I have this on my V6 mustang using the adapter available on this site. It looks wicked and sounds even better.


    Helpful (2) (0)

  • 4/5

    Installation Time: Full Day

    May 21, 2012

    Sounds and works Great

    Had to get it installed at a muffler shop as I don't have a flat driveway or room in the garage. Added the PaceSetter V6 Dual Exhaust Adapter Kit in front of this on my 2004 V6. Works great, more power and better mileage.


    Year: 2004 Submodel: V6 San Jose, CA, USA

    Helpful (1) (0)

  • 5/5

    August 18, 2009


    ive had them for about a month now and they are awesome. sound great feels better. worth the money.


    Helpful (2) (1)

  • 5/5

    Installation Time: Less than 1 Hour

    March 12, 2012


    i put this cat back on my mach 1 and with an off road h pipe and wow does it sound good, deep, loud, and just mean sounding


    Year: 2004 Submodel: Mach 1

    Helpful (1) (1)

  • 5/5

    April 10, 2010

    Worth the price

    Put this system on my 2000 GT after replacing the stock h-pipe with a BBK o/r x-pipe. The sounds is much better than the chambered mufflers and I highly recommend it to anyone.


    Year: 2000 Submodel: GT

    Helpful (2) (2)

  • 4/5

    Installation Time: Afternoon

    October 06, 2013

    Quality Materials - Poor fit w/aftermarket sway bar

    Although the quality of the materials in the kit are exceptional, there is not enough clearance if you have an aftermarket rear swaybar and lowering springs (Eibach Pro in my case). Even after making all the adjustments possible, going over any small or larger bump at over 5 MPH will result in the rear swaybar hitting the exhaust tubing. This effect is made worse with more weight in the car i.e. full tank of gas. It looks like I will have to have custom bent tubing made to properlty fix the issue meaning I wasted a bunch of money and should have just purchased the tips and mufflers instead of the full kit. Good horsepower increase - you will feel the difference.


    Year: 2004 Submodel: GT Southern Maryland

    Helpful (0) (1)

  • 5/5

    August 07, 2008

    Nice Sound

    I love the sound out of these Magnas.


    Helpful (0) (1)

  • 3/5

    April 13, 2008

    Not Loud Enough

    I had these installed when i bought my GT and i have a friend that has a mid pipe with this catback system and it sounds pretty good.... but if your looking for your car to be LOUD this is not the way to go...


    Helpful (2) (3)

  • 5/5

    January 25, 2008

    Top Dog!

    I plan on buying this exhaust again for my future V8 Stang!!


    Helpful (0) (1)

  • 3/5

    November 24, 2007


    Sweetness! Totally awesome sound!


    Helpful (0) (5)

  • 5/5

    Installation Time: Afternoon

    January 26, 2016

    Awesome sound and quality

    I bought the magnaflows to replace my old flowmasters. Installation was a breeze! No more drone! Quiet when at idle but when you get on it, it sounds great!


    Year: 2000 Submodel: GT MA

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    February 24, 2015

    Magnaflow Catback Long Term Performance

    No rust or discoloration anywhere on the entire system after 8 years of use so you know this system will last. I like the etched tips that I can only get from Magnaflow. They replaced one of mine that got damaged as long I as provided proof of purchase so they don’t just sell them to anyone. Also you can swivel the hanger to center the tip before final install so it looks right. Get compliments, not complaints, from the neighbors using it with FFRP shorty headers and Bassani x-pipe. No drone and really quiet in the car above 2500 rpm on the highway which makes this system a keeper.


    Year: 1999 Submodel: GT Manor, TX

    Helpful (0) (0)

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